Electret ion chamber-based passive radon-thoron discriminative monitor

Authors

P. Kotrappa
Daniel J. Steck, College of Saint Benedict/Saint John's UniversityFollow

Document Type

Article

Publication Date

9-2010

Disciplines

Health and Medical Physics | Physics

Abstract

Electret ion chambers (EICs), commercially available under brand name E-PERM^®, are widely used for measuring indoor and outdoor ²²²Rn concentrations in air. These are designed to respond only to ²²²Rn and not to ²²⁰Rn by restricting diffusional entry area. Such radon EIC (R EIC) monitors are modified by increasing the entry area to allow ²²⁰Rn, in addition to ²²²Rn. Such modified units are called RT EIC. When a set of R and RT EICs are collocated, it is possible to discriminate and measure both radon and thoron concentrations, using appropriate calibration factors (CFs) and algorithms. The EICs come in different volumes, providing different sensitivities. The thoron CFs for 58-, 210- and 960-ml volume R and RT pairs are, respectively, 2.8-, 18.7- and 89-V drop per (kBq m^-3 d), respectively. These provide much wider sensitivities and ranges compared to alpha track-based passive radon-thoron discriminative monitors.

Recommended Citation

Kotrappa P, Steck DJ. 2010. Electret ion chamber-based passive radon-thoron discriminative monitor. Radiation Protection Dosimetry 141(4): 386-389.